1. Field of the Invention
The invention relates to an oscillator circuit with an LC-parallel resonant circuit and a transistor (T1) as amplifier element.
2. Description of the Prior Art
Oscillator circuits with LC-parallel resonant circuits with different types of feedback circuits are known. An example of these is the so-called Colpitts oscillator, in which the feedback circuit between the amplifier element consisting of one or several bipolar or field effect transistors and the LC-parallel resonant circuit results from splitting the capacitance of the resonant circuit into two capacitors functioning at the end of the inductor of the resonant circuit. A problem with such oscillator circuits is temperature fluctuation, variations in frequency response as well as amplitude noise and phase noise resulting from this. These fluctuations can normally be attributed to changes in the operating point of the amplifier element.